const s1 = Symbol('二哈');
const s2 = Symbol('二哈');
console.log(s1 == s2);
const secretKey = Symbol('secret');
console.log(secretKey, '/////');
// 多人协作中 Why Symbol ?
// 动态   不太安全？
// key string 类型 ｜ Symbol 
const a = "ecut"
const user = {
  [secretKey]: '111222',
  email: '1232@163.com',
  name: '曹威威',
  "a":456,
  [a]: 123
}
console.log(user.ecut, user[a]);

user.email= 'weiwei@qq.com'